Input: add common DT binding for touchscreens

Add common DT binding documentation for touchscreen devices and
implement input_parse_touchscreen_of_params, which parses the common
properties and configures the input device accordingly.

The method currently does not interpret the axis inversion properties,
since there is no matching flag in the generic linux input device.

Reviewed-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
new file mode 100644 (file)
index 0000000..d8e0616
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
@@ -0,0 +1,27 @@
+General Touchscreen Properties:
+
+Optional properties for Touchscreens:
+ - touchscreen-size-x          : horizontal resolution of touchscreen
+                                 (in pixels)
+ - touchscreen-size-y          : vertical resolution of touchscreen
+                                 (in pixels)
+ - touchscreen-max-pressure    : maximum reported pressure (arbitrary range
+                                 dependent on the controller)
+ - touchscreen-fuzz-x          : horizontal noise value of the absolute input
+                                 device (in pixels)
+ - touchscreen-fuzz-y          : vertical noise value of the absolute input
+                                 device (in pixels)
+ - touchscreen-fuzz-pressure   : pressure noise value of the absolute input
+                                 device (arbitrary range dependent on the
+                                 controller)
+ - touchscreen-inverted-x      : X axis is inverted (boolean)
+ - touchscreen-inverted-y      : Y axis is inverted (boolean)
+
+Deprecated properties for Touchscreens:
+ - x-size                      : deprecated name for touchscreen-size-x
+ - y-size                      : deprecated name for touchscreen-size-y
+ - moving-threshold            : deprecated name for a combination of
+                                 touchscreen-fuzz-x and touchscreen-fuzz-y
+ - contact-threshold           : deprecated name for touchscreen-fuzz-pressure
+ - x-invert                    : deprecated name for touchscreen-inverted-x
+ - y-invert                    : deprecated name for touchscreen-inverted-y

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 43389c097b023f1f1c53f772cc60438b1dbc256d..8e07fe8505fdb0c6c20875006d0e75a08d8397be 100644 (file)
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -11,6 +11,10 @@ menuconfig INPUT_TOUCHSCREEN
 
 if INPUT_TOUCHSCREEN
 
+config OF_TOUCHSCREEN
+       def_tristate INPUT
+       depends on INPUT && OF
+
 config TOUCHSCREEN_88PM860X
        tristate "Marvell 88PM860x touchscreen"
        depends on MFD_88PM860X

diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 71a97559ce68924783037c7200bc36c83b33af08..4d479fb0a7686ee1e402cf539a3494dd2762cbf9 100644 (file)
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -6,6 +6,7 @@
 
 wm97xx-ts-y := wm97xx-core.o
 
+obj-$(CONFIG_OF_TOUCHSCREEN)           += of_touchscreen.o
 obj-$(CONFIG_TOUCHSCREEN_88PM860X)     += 88pm860x-ts.o
 obj-$(CONFIG_TOUCHSCREEN_AD7877)       += ad7877.o
 obj-$(CONFIG_TOUCHSCREEN_AD7879)       += ad7879.o

diff --git a/drivers/input/touchscreen/of_touchscreen.c b/drivers/input/touchscreen/of_touchscreen.c
new file mode 100644 (file)
index 0000000..f8f9b84
--- /dev/null
+++ b/drivers/input/touchscreen/of_touchscreen.c
@@ -0,0 +1,45 @@
+/*
+ *  Generic DT helper functions for touchscreen devices
+ *
+ *  Copyright (c) 2014 Sebastian Reichel <sre@kernel.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/of.h>
+#include <linux/input.h>
+#include <linux/input/touchscreen.h>
+
+/**
+ * touchscreen_parse_of_params - parse common touchscreen DT properties
+ * @dev: device that should be parsed
+ *
+ * This function parses common DT properties for touchscreens and setups the
+ * input device accordingly. The function keeps previously setuped default
+ * values if no value is specified via DT.
+ */
+void touchscreen_parse_of_params(struct input_dev *dev)
+{
+       struct device_node *np = dev->dev.parent->of_node;
+       struct input_absinfo *absinfo;
+
+       input_alloc_absinfo(dev);
+       if (!dev->absinfo)
+               return;
+
+       absinfo = &dev->absinfo[ABS_X];
+       of_property_read_u32(np, "touchscreen-size-x", &absinfo->maximum);
+       of_property_read_u32(np, "touchscreen-fuzz-x", &absinfo->fuzz);
+
+       absinfo = &dev->absinfo[ABS_Y];
+       of_property_read_u32(np, "touchscreen-size-y", &absinfo->maximum);
+       of_property_read_u32(np, "touchscreen-fuzz-y", &absinfo->fuzz);
+
+       absinfo = &dev->absinfo[ABS_PRESSURE];
+       of_property_read_u32(np, "touchscreen-max-pressure", &absinfo->maximum);
+       of_property_read_u32(np, "touchscreen-fuzz-pressure", &absinfo->fuzz);
+}
+EXPORT_SYMBOL(touchscreen_parse_of_params);

diff --git a/include/linux/input/touchscreen.h b/include/linux/input/touchscreen.h
new file mode 100644 (file)
index 0000000..08a5ef6
--- /dev/null
+++ b/include/linux/input/touchscreen.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2014 Sebastian Reichel <sre@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _TOUCHSCREEN_H
+#define _TOUCHSCREEN_H
+
+#include <linux/input.h>
+
+#ifdef CONFIG_OF
+void touchscreen_parse_of_params(struct input_dev *dev);
+#else
+static inline void touchscreen_parse_of_params(struct input_dev *dev)
+{
+}
+#endif
+
+#endif